Yes they do. But it depends on what the apps are and what they intend to teach. Many "educational" apps are more entertaining than educational and I believe a waste of time.
It is also highly beneficial to reinforce anything learn via apps by using concrete play, and if they are older a more workbook approach with real pencil and paper.
It is also highly beneficial to reinforce anything learn via apps by using concrete play, and if they are older a more workbook approach with real pencil and paper.
Apps that are "more entertaining than educational" can also have benefits, such as hand-eye coordination, motor skills, etc. But time should be limited and it depends a lot on the age of the child.
However, there is an interesting article here http://news.yahoo.com/benefit-mobile-apps-toddlers-questioned-153346597.html
Quote
"Everything we know about brain research and child development points away from using screens to educate babies," said Susan Linn, the group's director. "The research shows that machines and screen media are a really ineffective way of teaching a baby language. What babies need for healthy brain development is active play, hands-on creative play and face-to-face" interaction."